# Copyright (c) 2018 Presto Labs Pte. Ltd.
# Author: leon

import json
import logging
from typing import List, Union

from tornado import gen

import coin.flow.topic_map as topic_map
from coin.base.param_util import to_list
from coin.exchange.base.ws.subscriber import WebsocketJsonSubscriberBase
from coin.exchange.kraken_futures.kr_rest.futures_product import KrakenFuturesProduct


class KrakenFuturesSubscriber(WebsocketJsonSubscriberBase):
  def __init__(self,
               queue,
               group_id: str,
               worker_id: str,
               symbol: Union[List[str], str],
               close_callback=None,
               logger=None):
    super().__init__(close_callback, logger or logging.getLogger(__name__))
    self._symbol = to_list(symbol)

    self._register_url('wss://www.cryptofacilities.com/ws/v1')
    self._publisher = None
    self._init_publisher(queue, group_id, worker_id)

  def _init_publisher(self, queue, group_id: str, worker_id: str):
    topic_depth = topic_map.search_topic_id('kraken_futures_ws_depth_%s%s' %
                                            (group_id, worker_id))[0]
    topic_trade = topic_map.search_topic_id('kraken_futures_ws_trade_%s%s' %
                                            (group_id, worker_id))[0]

    self._publisher = {
        'book': queue.get_writer(topic_id=topic_depth[1]),
        'trade': queue.get_writer(topic_id=topic_trade[1])
    }

    self._enable_topic_event_publisher(queue,
                                       'kraken_futures_ws_topic_event',
                                       [topic_depth[0], topic_trade[0]])
    self._add_teardown_callback(self._teardown_publisher)

  @gen.coroutine
  def on_open(self):
    yield self._send_subscribe_request()

  @gen.coroutine
  def _send_subscribe_request(self):
    for symbol in self._symbol:
      product = KrakenFuturesProduct.FromStrNativeProduct(symbol)
      subscription_symbol = product.native_subscription_symbol
      self._logger.debug('Subscribing %s' % subscription_symbol)

      subscribe_depth_str = json.dumps({
          "event": "subscribe",
          "feed": "book",
          "product_ids": [subscription_symbol],
      })
      yield self._ws.write_message(subscribe_depth_str)

      subscribe_trade_str = json.dumps({
          "event": "subscribe",
          "feed": "trade",
          "product_ids": [subscription_symbol],
      })
      yield self._ws.write_message(subscribe_trade_str)
      yield gen.sleep(0.5)  # Sleep 0.5 second before next request

    self._publish_topic_event('START')
    self._logger.info('Subscribe done')

  def _teardown_publisher(self):
    if self._publisher:
      for _, publisher in self._publisher.items():
        publisher.close()
      self._publisher = None

  def on_message(self, timestamp: int, message: bytes):
    if self.stopped:
      return

    feed_type = None
    if isinstance(message, dict) and 'feed' in message:
      feed_type = message['feed']

    if feed_type == 'book' or feed_type == 'book_snapshot':
      self._publisher['book'].write(timestamp, message)
    elif feed_type == 'trade' or feed_type == 'trade_snapshot':
      self._publisher['trade'].write(timestamp, message)
    else:
      self._logger.error('Unknown message: %s' % message)
